Pressure cooker



March 27, 1934. F D CHAPMAN 1,952,419

PRES SURE COOKER Filed Nov. 27, 1931 A TTORNE Y.

Patented Mar. 27, 1934 UNITED STATES PATENT GFFC PRESSURE COOKER Frank D. Chapman, Berlin, Wis.

Application November 27, 1931, Serial No. 577,534

3 Claims. (Cl. 126-272) The present invention relates generally to improvements in the art of treating food products or the like after the same have been packed in receptacles, and relates more specifically to im- 5 provements in the construction and operation of cooking and sterilizing apparatus for heat treating substances concealed within cylindrical tin cans or similar containers.

An object of the invention is to provide improved heat treating apparatus which is simple in construction, and which is moreover highly efficient and flexible in operation.

Another object of the invention is to provide various improvements in the construction and operation of pressure cookers, whereby such devices may be utilized to effectively treat various commodities.

A further object of the invention is to provide apparatus which is especiallyuseful in conjunction with heat treating systems and processes wherein special liquids such as ethylene glycol or glycerin, are employed as a heat transferring medium. n

Still another object of the invention is to provide improved means for most elfectively distributing and applying heat to the containers treated in succession in a heat transfer system.

A further object of the invention is to provide various improvements in heat treating systems for canned foods, whereby the commodities may be most effectively treated in a minimum period of time.

These and other objects and advantages will be apparent from the following ,detailed description.

Some of the novel features of food processing with the aid of special liquids having characteristics diiering from those of pure water, shown and described but not specically claimed herein, form the subject of copending applications Serial No. 509,733, filed January 19, 1931; `Serial No. 509,734, led January 19, 1931; Serial No. 509,735, filed January 19, 1931; Serial No. 559,002, filed August 24, 1931; and Serial No. 563,125, led September .16, 1931.

A clear conception of embodiments of the' several features of 4novelty constituting the present invention, and of the construction and operation of heat treating apparatus built in accordance therewith, may be had by referring to the draw- .ing accompanying and forming a part of `this specification in which like reference characters designate the same or similar parts in the several views: Fig. 1 is a part sectional and somewhat diagrammatic side elevation of an improved continuous pressure cooker or sterilizer;

2 is an end elevation of the improved pressure cooker or sterilizer, looking toward the inlet end; and

Fig. 3 is an end elevation of the improved pressure cooker and sterilizer, looking toward rthe outlet end thereof.

While the present improvement has been illustrated and is described herein as being specifically applied to apparatus or systems for heating cylindrical tin cans containing uent food products such as milk or peas mixed with brine, with the aid of special treating solutions, it is vto be understood that the features of the inven- 7.0

tion are more generally applicable to the treatment of other commodities packed in other types of containers and subjected to treatment with other kinds of fluids than those specifically referred to.

Referring to the drawing, the improved pressure cooker o1' sterilizer comprises in general a hermetically sealed cylindrical normally stationary casing 10 having internal helical guides 11, and an elongated rotary drum 12 within the casing 10 having radial peripheral vaneslS adapted to propel food laden cylindrical tin cans 14 in succession along the guides 11 and spirally around and along the interior of the casing 10.

The main cylindrical casing 10 is disposed with its longitudinal axis adjustably inclined relative to the horizontal, and a zig-Zag can supply conduit l5 having an endless can conveyor 16 operable therethrough, communicates either with the bottom or with a side portion of the lowermost end of the inclined casing l0. Either the bottom or a side portion of the opposite uppermost end of the casing 10, communicates with a 'can discharge conduit 17 having an endless can conveyor 19 operable therethrough, and a can washer 20 associated with the upper portion of the discharge conduit 17 is adapted to wash the adhering treating liquid from the successive heat treated cans 14 prior to final delivery thereof from the apparatus. The speciiic manner in 100 which the successive cans 14 are delivered to the casing l0 from the supply conduit l5, and from `the casing l0 to the discharge conduit 17, is wellknown to those skilled in the art, and this transfer may be effected as shown in Fooks Patent No. 105 1,318,935.

The inlet and discharge conduits 15 and 17 are provided with suicient liquid to establish and maintain the desired pressure within the main casing 10, and the uppermost portion of the casllo ing 10 is provided with an air conning space 21 to and from which air may be admitted or withdrawn through a valve 18. The pressure of the air conned within the space 21 will obviously be dependent upon the head or level of the liquid within the conduits 15, i?, and the vertical thickness or height of the air space as well as the volume thereof may be varied by admitting or exhausting air through the valve 18 and by changing the inclination of the casing 10. Heat treating liquid or other medium, may be admitted to' the can delivery end of the casing 10, through a supply pipe 22, and the spent heating liquid may' be discharged from the casing 10 at any desiredv conveyors 16, 19 are operable by means'k of' gearin g24, 25, and the longitudinal inclination of the casing 10 may be varied at will without interfering with the normal operation o this gearing. The can discharge end of the casing 10 is swingably supported upon a bracket 26 by mea-ns of a pivot .27,Yand the can inlet end is verticallyv movable: by means of an adjusting screw 28 associated with a supporting bracket 29. By manipulating the screw 28, the can inlet end of the casing l0 may obviously be swung vertically about the pivot 27 to vary the longitudinal inclination of the casing 10 as; desired. The successive food laden cans 141 may bedeliveredto the upper end of the inlet conduit 15 by means of a supply chute 3G, and the nally treated and washed cans 14 may be discharged from the washer 20 to a delivery chute' 31.

Duringlnormal operation oi the improved cookeror sterilizer, thesuccessive food laden cans 14 are'adrnitted to the upper end of the zig-zag inlet conduit 15 and are conducted downwardly through the heating liquid therein, by'mez'ms` of the endless chain conveyor'l, being thus' preliminarily heated and being eventually delivered into the can supply end of the main casing 10. Heating liquid isadmitted to the interior of the casing` 10 around the'revolving drum 12, through the supply pipe 22, and the spent heating medium is discharged through the header 23'in a manner to maintain a uniform predetermined temperature 4and pressure within the heatv treating Zone. The volume of the air space 2'1 and the positionrthereof, is also iXed at any predetermined value, by admitting or withdrawing air through the valve 18 and by properly inclining the casingy 10'with the aid of the adjusting screw V28, and the level of liquid in the conduitsl 15, 17 is likewise maintained at a predetermined point.

As the preliminarily heated Vcans 14 enter the casing 10, the radial vanes i3 oi the rotating drum 12 Iadvance the san-1e around the interior of the casing 10 and along the helical guide 11, thus causing the product to be intermittently submerged in the heating liquid and alternately eX- posed to the air in the space 21. The space 21 may contain vapor, but the temperatureV of the gases within `this space may be considerably lower than that Aof the heating liquid in the lower portion of the casing 1).` This causes intermittent heating and cooling of the food laden cans, and also vcauses the cylindrical cans to be agitated more or less depending upon the length of time that they remain submerged, and also upon the depth yof submergence. .By varying the inclination of the casing 10, the cans may readily be agitated `to a greater extent'at one end of the casing 10, and viceversa, thus permitting most effective treatment of different kinds of commodities.

The heated cans 14 are subsequently delivered in succession from the discharge end. of the casing 10 and guide 11, into the lower end of the delivery conduit 17, where they are picked up by the endless conveyor 19 and are elevated through the liquid in the conduit 17. The product is thus initially cooled prior to delivery of the cans 14 to the atmosphere and to the can washer 20. In'the washer 20, the adhering treating liquid is removed and the inally treated and washed containers are eventually discharged through the chute v31;

From the foregoing description it will be apparent that the successive food laden cans 14 are automaticallyv first transported through the inlet conduit 15 wherein they are initially heated, aresub'sequently transported spirally around and longitudinally through the casing 10` where they are nally heat treated, and are finally transported through the discharge conduit 17 where they'are preliminarily cooled. 1f a heat treating liquidsuch as ethylene glycol, glycerol or a mixture of either or'b'otho'f these special liquids with water, is utilized, the degree of agitation of the cylindrical containers during transportation thereof through the casing 10, may be* readily varied to meet dii'erent requirements; The-*can washer 20 has its greatest utility when utilizing such special treating'liquids, and may ordinarily be dispensed with when pure water is employed as a heating medium. By varying thedepth or volume, and theposition o the air space 21, and

the pressure of thegasesv confined therein, various treating conditions may readilyr be'attained, thus insuring most emcient treatment of any commodity which it is found desirable to treat with the improved system. It should be noted that the aii` space 21 will permit maintenance of relatively high temperatures in the liquid basin at the lower portion of the casing 1G, without danger of degrading products which are apt to deteriorateif subjected to abnormally high temperatures for relatively long periods of -time without proper agitation. If the inlet end of the casing lois lower than the discharge end, the'heating liquid will submerge the cans to a greater extent at the inlet end than at the discharge end, and the degree of agitation of the advancing cylindrical cans will decrease, whereas, elevation of the inlet end above that of the outletend will reverse the agit'ative action. The temperature of the treating liquid within the casing 10" may also be varied as desired, and a higher temperature may be maintained at the discharge end of thecasing than at the inlet end thereof. Uniform temperature conditions should however be maintainedin order to insure uniformity in treatment of any particular commodity, and the mech-- anism for adjusting the inclination of the casing 10 to alter the characteristics of the air bubble or space 21 whereby the alternatevheating and cooling effect and the degree of agitation may be changed, obviously make this system highly flex- 1 In combination, an elongatedv circular caslio Aizo

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ing having a substantially horizontal longitudinal axis, inlet and discharge conduits rising from the opposite end portions of said casing, the lower portion of said casing and of said conduits containing liquid and said casing being formed to connel gases under pressure in the upper portion thereof above the liquid therein, rotary means coacting with said casing to transport objects in succession through said casing from said inlet to said discharge conduit and for alternately submerging the objects in said liquid and passing the same through said gases, and means for varying the inclination of said casing axis to vary the depth of said submergence at different points along said axis.

2. In combination, an elongated circular casing having a substantially horizontal longitudinal axis, inlet and discharge conduits rising from the opposite end portions of said casing, the lower portion of said casing and of said conduits containing liquid and said casing being formed to conne gases under pressure in the upper portion thereof above the liquid therein, rotary means coacting with said casing to transport objects in succession through said casing from said inlet to said discharge conduit along a helical path so as to alternately submerge the successive objects in said liquid and cause the same to pass through said gases, and means for varying the inclination of the axis of said path to change the depth of said submergence at different points along said path.

3. In combination, an elongated cylindrical casing having a substantially horizontal longitudinal axis, inlet and discharge conduits rising from the opposite ends of said casing, the lower portion of said casing and of said conduits containing liquid and said casing being formed to conne gases under pressure in the upper portion thereof above the liquid therein, a rotor having peripheral vanes coacting with said casing to transport cylindrical objects in succession through .said casing from said inlet to said discharge conduit along a'helical path so as to alternately and repeatedly submerge the successive objects in said liquid and cause the same to pass through said gases, and means for varying the inclination of the axis of said path to change the depth of said submergence at different points progressively along said path.

FRANK D. CHAPMAN. 

